How to switch to dark mode in Lutris? (Linux Mint 22)

I had Lutris in dark mode when I downloaded it. But 2 weeks ago, I changed the themes from default to:

Applications: Mint-x
Icons: Mint-X-Yellow
Desktop/panel: cinnamon

Now, when I am trying to change Lutris to dark mode, it has no effect, it is still in light mode.

I also tried this tutorial https://itsfoss.com/flatpak-app-apply-theme/, but it didn’t worked. I installed flatseal, added one line “filesystem” section, where I typed ~/.themes. And before it, I typed sudo flatpak override --filesystem=$HOME/.themes in terminal. But I forgot that I don’t have any theme in ~/.theme folder, so I changed that line to /usr/share/themes.
Then I created another line, now in “environment” section and typed GTK_THEME=Mint-L-Dark, but still didn’t work.
I don’t know what I did wrong. Can you help me please?

Did you try simply going to preferences→interface→theme and selecting dark? If that doesn’t work, see the pinned topic for reporting an issue, including logs and stuff